Reinforcing Bar Locking Device

ABSTRACT

A reinforcing bar locking device that can be easily locked at a position relatively far from an end portion of a reinforcing bar and apply a strong locking force to the reinforcing bar. The reinforcing bar ( 10 ) has a body member ( 11 ) having a through hole ( 11   a ) in which the reinforcing bar is insertable and also has a pair of fitting members ( 12 ) fitted between the reinforcing bar inserted into the through hole ( 11   a ) and the inner peripheral surface of the through hole ( 11   a ). The inner peripheral surface ( 11   b ) of the through hole ( 11   a ) is of a funnel shape whose diameter is reduced in the direction of the center axis (C). A female screw thread part ( 12   a ) with which the reinforcing bar engages is formed on the inner peripheral surface of the fitting member ( 12 ). The outer peripheral surface ( 12   b ) of the fitting member ( 12 ) is a conical surface that has surface contact with the inner peripheral surface ( 11   b ) of the body member ( 11 ). On the outer periphery of the body member ( 11 ), a substantially cylindrical inserting section ( 11   c ) and a flange section ( 11   d ) having a larger diameter than the inserting section ( 11   c ) are provided. Each of the fitting members ( 12 ) has a slit ( 12   c ) opened in the direction of the center axis (C) of the through hole ( 11   a ).

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a U.S. National Phase of International ApplicationPCT/JP2006/321651, filed Oct. 30, 2006, and claims the benefit offoreign priority under 35 U.S.C. §119 based on JP 2006-009843, filedJan. 18, 2006, the entire disclosures of which applications are herebyincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a reinforcing bar locking device forfixing a reinforcing bar inserted into a plurality of arrayed blockswhile applying a tensile force to the reinforcing bar, which can belocked with the reinforcing bar exposed from an end face of the blocks.

BACKGROUND ART

When a structure such as a block wall is built by stacking a pluralityof concrete blocks, a reinforcing bar inserted into the blocks so as torun through hollow portions or the like in the blocks is often fixedwhile applying a tensile force to the reinforcing bar in order toincrease the bonding force between the blocks. In this case, generally,the reinforcing bar is fixed by mounting a member having a function of awasher which is larger than the internal diameter of the hollow portionsor the like and a nut on the end portion of the reinforcing bar exposedfrom the end face of the blocks and by tightening the nut (see PatentDocument 1, for example).

Patent Document 1: Japanese Patent Publication No. S34-3622

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

As shown in Patent Document 1, by screwing and tightening a nut onto anend portion of a reinforcing bar protruding from an end face of a blockwhich is positioned uppermost on a group of stacked blocks, the group ofblocks can be fixed while applying a tensile force to the reinforcingbar. However, when the end portion of the reinforcing bar exposed fromthe end face of the block is long, the nut screwed onto the end portionof the reinforcing bar needs to be turned many times until the nutreaches the desired position on the end face of the block. Therefore,the operation of mounting the nut on the reinforcing bar is troublesomeand takes a long time.

Accordingly, where a large number of reinforcing bars are used, forexample, in building a large structure, a considerable amount of troubleand time is consumed in the operation of screwing and tightening thenuts onto the end portions of the reinforcing bars.

An object of the present invention is to provide a reinforcing barlocking device which can be easily locked at a position relatively farfrom an end portion of a reinforcing bar and apply a relatively stronglocking force to the reinforcing bar.

Means for Solving the Problems

A reinforcing bar locking device according to the present inventioncomprises a body member having a through hole in which a reinforcing baris insertable; a plurality of fitting members which are fitted betweenthe reinforcing bar inserted into the through hole and an innerperipheral surface of the through hole, the inner peripheral surface ofthe through hole having a funnel shape whose diameter is reduced in adirection of a center axis; an engaging section which engages with thereinforcing bar formed on an inner peripheral surface of the fittingmembers; and a conical surface which has surface contact with the innerperipheral surface of the body member formed on at least a part of anouter peripheral surface of the fitting members.

By the above structure, the reinforcing bar locking device can be lockedat a desired position on a reinforcing bar in the following process.First, a body member is mounted so that an end portion of a reinforcingbar protruding from an end face of a block penetrates from a smalleropening to a larger opening of a through hole of the body member. Afterthe body member is moved along the reinforcing bar up to the end face ofthe block, a tensile force is applied to the reinforcing bar. Next, aplurality of fitting members are fitted between the reinforcing bar andan inner peripheral surface of the through hole while an engagingsection of the fitting members is engaged with the reinforcing bar.Then, the tensile force applied to the reinforcing bar is released. Inthis way, the reinforcing bar contracts in a direction of a center axisso that the plurality of fitting members are pulled in a directiontoward the reduced diameter of the through hole while engaging with thereinforcing bar, and a conical surface on an outer peripheral surface ofthe fitting members is brought into surface contact with the innerperipheral surface of the through hole of the body member and locked.Thus, the reinforcing bar locking device is locked at the desiredposition of the reinforcing bar (on the end face of the block, forexample) so as not to move.

In the above case, the body member mounted from the end portion of thereinforcing bar can be moved to the end face of the block withoutturning the body member. Therefore, the body member can be easily lockedeven at a position far from the end portion of the reinforcing bar.Furthermore, the reinforcing bar, the fitting members, and the bodymember can be locked in an integrated manner with the contracting forceof the reinforcing bar after releasing the tensile force, which exhibitsa relatively strong locking force applied to the reinforcing bar. It isalso possible to interpose a washer member having a through hole for thereinforcing bar between the body member of the reinforcing bar lockingdevice of the present invention and the end face of the block.

As the engaging section, preferably, a female screw thread part which isscrewed onto a male screw part formed on an outer peripheral surface ofthe reinforcing bar may be provided on the inner peripheral surface ofthe fitting member. By this structure, the fitting member can firmlyengage with the reinforcing bar, which enhances the locking force withthe reinforcing bar.

Furthermore, the fitting member may be further provided with a slitwhich is opened in the direction of the center axis of the through hole.By this structure, after the tensile force is released, when thereinforcing bar and the fitting member move in the direction toward thereduced diameter of the through hole, the fitting member itself isdeformable so as to reduce its diameter due to a surface pressureapplied from the inner peripheral surface of the through hole.Therefore, a clamping force applied to the reinforcing bar by thefitting member is increased, resulting in further enhancement of thelocking force to the reinforcing bar.

In the meantime, the body member may be provided with, on an outerperiphery thereof, at least a pair of flat parts arranged in parallelwith each other on opposite sides of the center axis of the throughhole. By this structure, a tool such as a wrench can engage with theflat parts of the body member to turn the body member. Thus, thereinforcing bar locking device locked on the reinforcing bar can betightened or loosened using a wrench or the like.

EFFECTS OF THE INVENTION

The present invention can provide a reinforcing bar locking device whichcan be easily locked at a position relatively far from an end portion ofa reinforcing bar and apply a strong locking force to the reinforcingbar.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating a reinforcing bar locking device ofan embodiment of the present invention;

FIG. 2 is a front view of the reinforcing bar locking device shown inFIG. 1;

FIG. 3 is a sectional view taken along the line A-A in FIG. 1;

FIG. 4 is an exploded view of the reinforcing bar locking device shownin FIG. 3;

FIG. 5 is a plan view of a body member which constitutes the reinforcingbar locking device shown in FIG. 1;

FIG. 6 is a front view of the body member shown in FIG. 5;

FIG. 7 is a plan view of a fitting member which constitutes thereinforcing bar locking device shown in FIG. 1;

FIG. 8 is a front view of the fitting member shown in FIG. 7;

FIG. 9 is a bottom view of the fitting member shown in FIG. 7;

FIG. 10 is a view illustrating the reinforcing bar locking device ofFIG. 1 in use;

FIG. 11 is a view illustrating the reinforcing bar locking device ofFIG. 1 in use;

FIG. 12 is a view illustrating the reinforcing bar locking device ofFIG. 1 in use;

FIG. 13 is a plan view illustrating a reinforcing bar locking device ofanother embodiment of the present invention; and

FIG. 14 is a plan view illustrating a reinforcing bar locking device ofyet another embodiment of the present invention.

DESCRIPTION OF REFERENCE NUMERALS AND SYMBOLS

-   -   10, 20, 30: reinforcing bar locking device    -   11, 21, 31: body member    -   11 a: through hole    -   11 b: inner peripheral surface    -   11 c: inserting section    -   11 d: flange section    -   11 f: smaller opening    -   11 g: larger opening    -   12: fitting member    -   12 a: female screw thread part    -   12 b: outer peripheral surface    -   12 c: slit    -   13: reinforcing bar    -   13 a: male screw part    -   13 b: end portion    -   14: block    -   14 a: hollow part    -   14 b: end face    -   15: plate member    -   15 a: locking hole    -   21 a, 31 a: flat part    -   C: center axis    -   T: tensile force

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention is explained below with referenceto the drawings.

As shown in FIGS. 1 to 10, a reinforcing bar locking device 10 of thepresent embodiment includes a body member 11 having a through hole 11 ain which a reinforcing bar 13 is inserted and a pair of fitting members12 which is fitted between the reinforcing bar 13 inserted into thethrough hole 11 a and an inner peripheral surface of the through hole 11a. An inner peripheral surface 11 b of the through hole 11 a has afunnel shape whose diameter is reduced in a direction of a center axis.On an inner peripheral surface of the fitting member 12, a female screwthread part 12 a is provided as an engaging section with the reinforcingbar 13. An outer peripheral surface 12 b of the fitting member 12 isformed in a conical surface which has surface contact with the innerperipheral surface 11 b of the body member 11. On an outer periphery ofthe body member 11, an inserting section 11 c which has a substantiallycylindrical shape and a flange section 11 d which has a larger externaldiameter than the inserting section 11 c are provided.

The two fitting members 12 are positioned to oppose each other so thatan outer appearance of the fitting members 12 forms an inverted,substantially truncated conical shape, and are inserted into the throughhole 11 a of the body member 11. Inside the through hole 11 a, thefemale screw thread part 12 a on the inner peripheral surface of thefitting members 12 is screwed onto a male screw part 13 a formed on anouter peripheral surface of the reinforcing member 13, thereby clampingthe reinforcing bar 13. In each of the fitting members 12, a slit 12 cis formed in the direction along the center axis C of the through hole11 a. The slit 12 c is opened from an upper end toward a lower end ofthe fitting member 12. A length of the slit 12 c is approximately 65 to75% of a length of the fitting member 12 in the direction of the centeraxis C but is not limited to this length.

Next, referring to FIGS. 10 to 12, a use of the reinforcing bar lockingdevice 10 is explained below. FIGS. 10 to 12 illustrate an example ofconstruction where the reinforcing bar 13 is inserted into a hollow part14 a of stacked concrete blocks 14 and fixed while applying a tensileforce to the reinforcing bar 13.

As shown in FIG. 10, on an end face 14 b of the block 14 positioneduppermost, a plate member 15 having a function of a washer is placed.The plate member 15 has a locking hole 15 a which has a smaller diameterthan the hollow part 14 a and allows the reinforcing bar 13 to passtherethrough. An end portion 13 b of the reinforcing bar 13 insertedinto the hollow part 14 a projects from the locking hole 15 a of theplate member 15. A lower end portion (not shown) of the reinforcing bar13 is fixed to an end face of a block positioned lowermost (not shown).The body member 11 is mounted so that the end portion 13 b of thereinforcing bar 13 passes through the through hole 11 a of the bodymember 11 from a smaller opening 11 f to a larger opening 11 g. Then,the body member 11 is moved along the reinforcing bar 13 up to the platemember 15 on the end face 14 b of the block 14, and the insertingsection 11 c of the body member 11 is inserted into the locking hole 15a of the plate member 15, resulting in the state where the flangesection 11 d protrudes from an upper face of the plate member 15.

Next, a conventional hydraulic jack (not shown) is set on a side of theend portion 13 b of the reinforcing bar 13 to apply a tensile force T tothe reinforcing bar 13. Then, as shown in FIG. 11, the two fittingmembers 12 are fit between the reinforcing bar 13 and the innerperipheral surface 11 b of the through hole 11 a of the body member 11,and clamp the reinforcing bar 13. In this case, the female screw threadpart 12 a which is an engaging section of the fitting member 12 (seeFIG. 4) is screwed onto the male screw part 13 a on the outer peripheralsurface of the reinforcing bar 13. Thus, as shown in FIG. 11, an upperend portion of the fitting member 12 in the reinforcing bar lockingdevice 10 is rendered somewhat protruding from the larger opening 11 gof the body member 11.

After that, the tensile force T applied to the reinforcing bar 13 isreleased. Then, as the reinforcing bar 13 contracts in its longitudinaldirection, the plurality of fitting members 12 are pulled in a directiontoward the reduced diameter of the through hole 11 a of the body member11 as shown in FIG. 12 while the plurality of fitting members 12 aremaintained to engage with the reinforcing bar 13, and the outerperipheral surface 12 b (conical surface) of the fitting members 12 isbrought into surface contact with the inner peripheral surface 11 b ofthe through hole 11 a of the body member 11 and locked thereon.Accordingly, since the reinforcing bar locking device 10 is fixed on theend face 14 b of the block 14 while being locked with the reinforcingbar 13, the reinforcing bar 13 is fixed while the tensile force is beingapplied to the reinforcing bar 13.

By using the reinforcing bar locking device 10, the body member 11mounted from the end portion 13 b of the reinforcing bar 13 can be movedup to the end face 14 b of the block 14 without turning the body member11 at all. Therefore, the body member 11 can be easily locked at aposition relatively far from the end portion 13 b of the reinforcing bar13. Moreover, with the contracting force of the reinforcing bar 13 afterreleasing the tensile force T, the reinforcing bar 13, the fittingmember 12, and the body member 11 are locked in an integrated manner,which exhibits a strong locking force applied to the reinforcing bar 13.

In addition, as shown in FIGS. 3 and 4, the female screw thread part 12a which engages with the male screw part 13 a formed on the outerperipheral surface of the reinforcing bar 13 is formed on the innerperipheral surface of the fitting member 12 as the engaging section.Therefore, the fitting member 12 and the reinforcing bar 13 can befirmly engaged with each other, applying a strong locking force to thereinforcing bar 13. Furthermore, as shown in FIGS. 7 to 9 and otherfigures, the slit 12 c is opened in each of the pair of fitting members12. Thus, when the reinforcing bar 13 and the fitting members 12 move inthe direction toward the reduced diameter of the through hole 11 a ofthe body member 11 by the contracting force of the reinforcing bar 13after the tensile force T is released, the fitting members 12 themselvesare deformable so as to reduce their diameter due to a surface pressureapplied by the inner peripheral surface 11 b of the through hole 11 a.Accordingly, a clamping action of the fitting members 12 exerted ontothe reinforcing bar 13 is increased, thereby exhibiting an extremelystrong locking force to the reinforcing bar 13.

Next, with reference to FIGS. 13 and 14, other embodiments of thepresent invention are explained below. In reinforcing bar lockingdevices 20 and 30 shown in FIGS. 13 and 14, the members having the samefunctions and effects as those of the members of the above-describedreinforcing bar locking device 10 bear the same reference numerals as inFIGS. 1 to 12, and the explanation thereof is omitted.

The reinforcing bar locking device 20 shown in FIG. 13 has a pair offlat parts 21 a formed on an outer periphery of a body member 21. Theflat parts 21 a are arranged in parallel with each other on oppositesides of a center axis C of a through hole 11 a. The reinforcing barlocking device 30 shown in FIG. 14 has three pairs of flat parts 31 aformed on an outer periphery of a body member 31. Each pair of the flatparts 31 a are arranged in parallel with each other on opposite sides ofa center axis C of a through hole 11 a.

In the above structures, the body members 21 and 31 can be turned byengaging a tool such as a wrench (not shown) with the flat parts 21 aand 31 a of the body members 21 and 31. Therefore, it is possible totighten or loosen the reinforcing bar locking devices 20 and 30 lockedwith the reinforcing bar 13 as shown in FIG. 12 using a wrench or thelike according to need. The advantages and effects of other members arethe same as those of the reinforcing bar locking device 10 describedabove.

INDUSTRIAL APPLICABILITY

The reinforcing bar locking device of the present invention is widelyapplicable in the construction industry or the like where various kindsof structures are constructed by fixing a reinforcing bar inserted intoa plurality of arrayed blocks while applying a tensile force to thereinforcing bar.

1. A reinforcing bar locking device comprising: a body member having athrough hole in which a reinforcing bar is insertable; a plurality offitting members which are fitted between the reinforcing bar insertedinto the through hole and an inner peripheral surface of the throughhole, the inner peripheral surface of the through hole having a funnelshape whose diameter is reduced in a direction of a center axis; anengaging section which engages with the reinforcing bar formed on aninner peripheral surface of the fitting members; and a conical surfacewhich has surface contact with the inner peripheral surface of the bodymember formed on at least a part of an outer peripheral surface of thefitting members.
 2. The reinforcing bar locking device according toclaim 1, wherein the engaging section is a female screw thread partprovided on the inner peripheral surface of the fitting members, thefemale screw thread part being screwed onto a male screw part formed onan outer peripheral surface of the reinforcing bar.
 3. The reinforcingbar locking device according to claim 1, wherein the fitting membershave a slit opened in the direction of the center axis of the throughhole.
 4. The reinforcing bar locking device according to claim 1,wherein the body member has at least a pair of flat parts arranged inparallel with each other on opposite sides of the center axis of thethrough hole on an outer periphery of the body member.